At Canonical, one of the approaches taken to accelerate development is to hold coding sprints (otherwise known as hackathons, hackfests or similar). Certain things get done a lot quicker face to face compared to mailing lists, IRC or VoIP.

When collaborating with someone at one of these sprints the usual way to let others look at my work would be to commit the changes so that they could be pulled or merged by others. With legacy version control systems like CVS or Subversion, this would generally result in me uploading all my changes to a server in another country only for them to be downloaded back to the sprint location by others.

When at conferences and sprints, I often want to see what someone else is working on, or to let other people see what I am working on. Usually we end up pushing up to a shared server and using that as a way to exchange branches. However, this can be quite frustrating when competing for outside bandwidth when at a conference.

It is possible to share the branch from a local web server, but that still means you need to work out the addressing issues.

So after I posted some instructions for setting up Avahi on Breezy, a fair number of people at UBZ did so. For most people this worked fine, but it seems that a few people's systems started spewing a lot of network traffic.

It turns out that the problem was actually caused by the zeroconf package (which I did not suggest installing) rather than Avahi. The zeroconf package is not needed for service discovery or .local name lookup, so if you are at UBZ you should remove the package or suffer the wrath of Elmo.

During conferences, it is often useful to be able to connect to connect to other people's machines (e.g. for collaborative editing sessions with Gobby). This is a place where mDNS hostname resolution can come in handy, so you don't need to remember IP addresses.

This is quite easy to set up on Breezy:

• Install the avahi-daemon, avahi-utils and libnss-mdns packages from universe.
• Restart dbus in order for the new system bus security policies to take effect with "sudo invoke-rc.d dbus restart".
• Start avahi-daemon with "sudo invoke-rc.d avahi-daemon start".
• Edit /etc/nsswitch.conf, and add "mdns" to the end of the "hosts:" line.

Now your hostname should be advertised to the local network, and you can connect to other hosts by name (of the form hostname.local). You can also get a list of the currently advertised hosts and services with the avahi-discover program.